Shock absorber



J. M. HALL SHOCK ABsoRBER Sept; 30, 193);

:s snets-sheet 1 Filed Nov. '7, 1921 env-r' wma@ @MM Sept. 30, 1930. J, M, HALL 1,776,972

SHOCK ABSORBER I Filed Nov. 7, 1921 3 Sheets-sheei` 2 Fig. 4.

4765239 iHv-56I J. M. HALL Sept. 30, 1930.

SHOCK ABSORBER 3 Sheets-Sheet Filed NOV. '7, 1921 Patented Sept. 30,v 1930 l UNITED STATES PATENToFI-lca JOSEPH M. HATL, F HAMILTON, ONTARIO. CANADA, ASSIGNOR TO HALL DRAFT GEAR CORPORATON, OF BUFFALO, NEW YORK, A CORPORATION 0F NEW YORK snocx ABsoRBER 'This inventionrelates to an apparatus for .absorbing shock and preventing undue jarring, and possible breaking of parts subjectsuddenly relativelyto each other, as for instance, when a railway car is started or stopped or coupled with another car, andlalso:

in the case of an 'automobile`while running over an uneven road. r

particularly Vwhen organized for railway service, is t'o employ a plurality of .co-operat-,-

.- ing friction plates in such manner that they do not wear appreciably by abrasion and v therefore have along life and also present an unusually extensiyeffrictional surface forab-4 sorbing the load orshock.

, Another object of this invention is to Isimplify the construction and reduce the cost of manufacture byfmaking the friction plates from rolled metal plates which are parallel sided andy do Iiot'require any machining.

A furtherlobject of this invention is to sef cure a high frictional'resistance while: the

comparatively low pressure andv thus reduce wear to.l a minimum.

form a complete assembled unit. ready for installation in a car insteadnof requiring the parts to be shipped. dismembered and-parts l added'thereto at the place'f installation and also to arrange the 4several parts that the same are self aligning and do notdepend on the car to keep the same in place while in action.^'

' In the accompany-nigdrawings: l

Figure 1 is a horizontal'longitudinal section, taken on line 1 1, Fig-3, and showing my invention organized for use as a friction shock absorbing gear for railway cars, the

. parts being represented in the position which y f they 'occupy when the 'gear is released. Fig ure2 is a similar view showing the gear under- The chief object of this Shock abserbef,

t-hereon and 33 the transverse car co-operating' friction elements are under:

application mea november 7, 1921.' serial No. 513,220.

a load completely compressed. Figures 3 and 4-are vertical longitudinal sections taken on fthe correspondingly numberedflines in Fig. edtq a quick force when twobodies are moved 1.. .Figures 5 and 6- are vertical transverse sections, taken on lines 5 5, and 6 6, Fig. 1,' respectively. Figures 7 8, 9, 10, 11 and 12 are perspective vlews of some parts of the shock labsorbing mechanismshown in Figs.

1`6. Similar characters of reference refer to like vparts throughout the several views.

The embodimentA of my .improved 'shock absorber or friction gear for use in railway car service shown in the drawings as a practical` embodiment of my invention is con-1 structed as'follows:

. 30 represents the longitudinal center sills of a car frame', 31 the front draft lugs or `stops on the front parts of the opposing sides of these sills, 32 the rear draft Vlugs or stops ing bar or iron connecting the lower sides o the sills between the front and rear draft lugs and Iadapted to support the shock absorber or gear and associated parts on the underside of the same.

represents the shank of a car coupler which has its rear end arranged between the longitudinal arms 35 at the front end of a -yoke 36 and connected therewithby a transverse key 37, the lower side of said yoke resting slidingly on said carrying bar 33.

Arranged between the sills adjacent to the front and rear draft lugs and extending through the yoke are the front and rear followers, buierfheads or members each of which is preferably constructed in the form of a hollow box or'casing which is rectangular in cross section. The front buffer head or member comprises two vertical longitudinal 4side walls 38, upper and lower horizontal longitudinal walls 39, and avertical transversefront wall 40 connecting the front ends of the longitudinal walls 38, 39. This front buferhead extends transversely through the .front part of a longitudinal slot 41 1n the yoke andis adapted to engageits front side with the front end 42 of ythis slot and also with the front draft lugs 31 and the rear end of the couplershank 34. The rear buffer head comprises two vertical longitudinal side walls 43, upper and lower horizontal longitudinal walls 44, and a vertical transverse rear wall 45 connecting the rear ends of the longitudinal walls 43, 44. The rear buffer head extends transversely through the rear part of the slot 4l in the yoke and is adapted to bear on its rear sidev against the rear end 141 of this slot and also against the rear draft lugs 32. The vertical longitudinal walls of the two buffer heads bear slidingly on their outer .sides against the opposing longitudinal surfaces of the sills and are thus confined against lateral movement while effecting their longitudinal movement upon working andreleasing the shock absorber. v

Within the two buffer heads are arranged a plurality of friction elements Wvhich are adapted to frictionally engage each other with a longitudinal sliding movement relatively to each other and serve as a means for absorbing or taking up the shock. work or load during buiiing and pulling strains when coupling or pushing the car or when pulling the same. These friction elements are preferably constructed in form of flat friction plates 46 of metal, each of which has its opposite ilat longitudinal sides made parallel. A plurality of pairs of sets of such friction plates are employed, the sets of one pair being arranged lengthwise within the two buffer heads on one side thereof and the sets of the other pair within these heads on the other side thereof so that the two pairs are separated by an intervening'longitudinal space.

The friction plates of one set of one pair alternate lwith friction plates of the companion set sothat these plates overlap one another and engage theiry Hat surfaces with '-one another in a direction parallel and lengthwise of the direction of movement of the coupler and associated" arts. The front ends of the front sets ofbth pairs 'of fric tion plates are adapted to beengaged by the transverse wall of the front buffer head and the rear ends of the rear sets of both pairs of friction plates are adapted to be engaged by the transverse wall of the rear buffer head. Each of these friction plates is provided on opposite edges of itsqouter end with an inwardly facing releasing shoulder 47 which is preferably produced by forming notches 48 inthe edge of these plates, these shoulders on the corresponding` ends of the several sets of friction p lates being transverselydijn line with each other. Y' Y On the inner longitudinal side of each pair of sets of friction plates adjacent to opposite ends thereof, the same are engaged by two wedge plates 148 of metal, each of which is adapted to press transversely outward and also engage the same with a limited longitu- A'blocks is provided with outwardly facing dinal sliding movement. On its' inner side each of these wedge-plates is provided with an incline orv wedge surface 49 and an abrupt 'space between the pairs of friction plates and wedge platea-each of these blocks be,-v

ing'provided at its inner end on its horizontally opposite side with inelines or wedge surfaces 55 which converge inwardly and engage with the correspondingly inclined lfaces on the -pair of wedge plates at the adjacent endsv of the pairs of friction plates while the outer end of this wedge block bears against the transverse wall of the adjacent butler head and `is held in a central position relatively thereto by providing the respective buffer head on the .inner side of its end wall withjasock'et 56 which receives the outer end of the companion wedge block and retains the'latter against transverse displacement.

57 represents a main spring which yieldingly resists the inward relative longitudinal movement of the front and rear wedge plates toward each other which spring is preferably of helical form and arranged .within the space between the pairs of friction plates and the wedge plates associated therewith. At its front end the'maln spring operates on the front companion wedge plates by means of a front bridge plate 58 arranged transversely and engaging at its opposite edges with the inwardly facing shoulders 5() of the front wedge plates and engaging with the front end of the main spring. A similar bridge plate 59 isinterposed between the rear end of the main springand the inwardly facing shoulders 50 of lthe rear wedge plates. By this means a single main spring means co-operates with the wedge plates at the front and rear end of the shock absorber.

The opposite ends of each bridge plate are conned against displacement betweenfthe side flange 52 of the adjacent wedge plates.

60, 61 represent the inner' and outer helical sections of a nested Vreleasing spring which is arranged lengthwise within the main spring and which extends through openings 62 in-the bridge plates and is seated in its opposite ends in asocket 63 formed -in the inner ends ofthe wedge blocks for `retaining Athis spring in place.

On its opposite sides each of the wedge shoulders 64 and the corresponding opposite sides of the'adjacent wedge plates are lll! :coupling bars which are arrange versely on opposlte sides of the front and also provided with similar outwardly facing shoulders see Fig. 10.

66, 67 represent'front-and rear airs of transrear ends of the several pairs of friction 'plates so that each end of one of these bars visfgwithin the corresponding notches 48 of "oIiefset' of friction plates and theouter edge of this bar faces the shoulders 47 on these plates while the inner edge of this bar faces the shoulders 64 and 65 of the respective wedge block and wedge plates.- The free innerendofeach friction plate is contractedv or reduced in width, as shown at 68, so that the same clears the couplingY bars associated with the other sets of-friction plates.` The vertical longitudinal ,wallsof the buffer heads are preferably provided on their inner sides with longitudinal grooves G9 into whichv the ends'- of the coupling bars 66, 67 project which permits of making the latter suiiicently'long to engage fully at all times with the friction plates and still avoid yengagement ofthese bars at their ends with the buier heads.

Operation When the shock absorber is fully relaxed or released the several parts are in the position shown in Figs. 1, 3 and 4 in'which the front and rear buer heads or followers engage with the front and rear draftflugs on the sills, the two sets of friction plates of each pair are drawn apart their fullestv extent, the front and rear wedge blocks and .wedge plates are separated th`e maximum distance so that the end walls ofthe buffer heads do not engage the outer ends of the friction plates, the coupling bars engage the releasing shoulders 47 ofthe friction plates,

and the releasing and main springsi are eX- panded as far as possible within the prescribed` limits and are now only under their initial tension imposed upon them when the gear was assembled orinstalled. l

If now a' pushing force is applied to the car coupler when coupling two cars of a train or when stopping the movement of the same thefirst effect is to push the front buffer head or follower backwardly together with the .front 'wedge blockwhich movement takes place without actuating'the friction plates inasmuch as a slight clearance exists between. the end wall of the front buffer head and the front. or outer ends of the front friction plates prior to beginning the backward movement of the frontbutfer head, as shown in Figs. 1 and 3. During this initial backward movement of the front buer head and wedge block the releasing spring is increasingly strained and both 4the front and rear wedge plates are pressed laterally outward in a dlrection perpendicular or at right angles to 65 the direction of movement of the front buifer `head and wedge block bythe wedge action of the front wedge block against the front wedge plates and the wedge action of the rear wedge block against the rear wedge plates. In this instance Athe force is transmitted directly from the front wedge block to the front wedge plates, the backward movement of which'latter is yieldingly resisted by the main spring, while this force istransmitted indirectly to the rear=wedge plates which receive the longitudinal pressure from the main spring and engage wedging'ly with the rear wedge block which latter at this time forms a stationary abutment. By this means the lateral pressure ofboth of the front and rear wedge plates is alike inasmuch as the same is dependent upon the tension of the same main of each .pair are pressed and an increased frictional engagement is effected between the opposing flat sides of the same. After this increased pressure between the several cooperating friction plates the front buffer head during its continued backward movement under the bufng or pushing force engages the front ends of the front sets of friction plates and causes the latter to move backwardly between the rear sets of friction plates which are in frictional engagement therewith, thus resisting such backwardl movement and cushioning the shock of the load or work in this direction.l As the backward movement of the front buier head continues the front wedge plates are also moved in this direction by the front wedge block which has the effect of still further increasl ing the tension of the main spring which in turn operates to increase the wed e actionof both the front and rear wedge locks on the front and rear wedge plates so'that the latter are pressed with increasin greater frictional engagement between the front and rear friction plates, thus further building up the frictional resistance to the Vbackward movement of the front buffer head under the load which produces this movement. The resistance of the shock absorber is thus gradually increased in the same measure as the front buffer head advances toward the rear bilder head until these heads finally engage each other at their Opposing ends,

as shown in Fig. 2, when the maximum shock absorbing capacity of the apparatus has been reached, thereby bringing the load to a state of rest gradually and with a minimum shock to the rigid parts of the car which carry the shock absorbing device and to the cargo or passengers carried by the car. During this force laterally and produce a proportionately ment of the outer longitudinal edges with the shoulders 47 of the front friction plates.

During the initial part of the inward movement of the front sets offriction plates, wedge plates and associated parts when su b jected to a buiiing load, therear sets of friction platesgand wedge plates are also carried inwardly or rearwardly for a short distanceuntil the outer or rear ends of the rear sets of friction plates engage the rear follower 45, as shown in Fig. 2, after which they remain stationary and the front .friction plates slide on the rear plates during the remaining buiiin action of the gear.

During the st part of the forward or out-` ward movement of'lthe' front sets of friction plates, upon removing the buiiing compression on the mechanism, the' rear sets of fricfriction plates until thel slack between the rear friction plates and the rear release bars- 67 has been taken up after which the rear friction plates are held stationary, and the front friction plates complete their forward movement independently ofthe rear friction plates, whereby the front friction plates slide forwardly relative to the rear friction plates until the mechanism is fully released and bothl the front and rear sets of friction plates have their outer ends spaced from their respective 'followers 40, 45 as shown in Fig.v 1.

,Upon cessation of the backward pressure of the loaden the front buffer head the first effect is ,a forward. movement of the front 'buffer head under the action of the releasing spring which is independent of the wedge plates and friction plates which has the effect of slightly reducing the lateral pressure of the friction plates against each other by reason of the fact that the slight expansion of the main spring correspondingly weakens the same and produces a proportionately less powerful wedge action between the wedge plates and wedge blocks. Asthe 'front wedge block gradually recedes it is followed by the front wedge plates which are pressed forward by the main spring, so that the force of the wedge action continues'to gradually reduce, accompanied bya reduction of the same measure in the frictional. contact between the several frictionl plates as the tension of the main spring gradually becomes less until the front'bufer v-head reaches the end of its forward movement against the front draft lugs. The first part of the forward releasing movement of-'the front buffer head and front wedge block takes place independently of-the front friction plates in order to first slightly reduce the lateral pressure of the wedge plates against the' friction plates and relieve thefrictional contact between the same. During the forward movement of the front buffer head and front wedge block after the transverse wedge pressure of the wedge plates or shoes 148 against the friction plates has ,been relieved, the wedge plates or shoes 148 are moved forwardly or outwardly by the main spring resistance 57 and at the same time the front sets of friction plates are also carried forwardly by the main spring 57, due to the shoulders on the front wedge plates or shoes engaging with the releasing bars 66,

which bars in turn engage the shoulders 47 of the front friction plates whereby the latter are moved forwardly relative to the rear friction plates into their foremost position preparatory to effecting the next buff absorbing action. As the front wedge plates gradually move away from the rear wedge plates the main spring, although becoming gradually weaker and less effective, still exerts a sufiiciently high lengthwise pressure against the wedge platesto maintain such a lateral pressure on `the friction` plates as will hold them under such a `degree`-of frictional contact as to prevent a sudden release of the friction draft gear but compel the same to operate gradually and thus avoid the undesirable results which otherwise4 would ensue.

'If during the forward or outward movement of the front buffer head and wedge block the front friction plates'should stick frictionallyto the rear friction'plates and not move forwardly or only sluggishly or if the front friction `plates should become shifted into a non-straight position then the shoulders 64 of the front wedgeV block will also engage the releasing bars 66 which bars engage the shoulders 47 of the front friction plates and cause the resilience of the release spring resistance 60, 61 to assist the main spring 57 in thel work of pulling the front friction pates forwardly away from the rear friction p ates. i

The shoulders 64 on the wedge blocks 53, 54 do not perform any function wh atever during normal operation of the gear either while the same is being compressed or while being released. These shoulders .64 only come into play in case of an emergency, for example, when the friction plates act slowly due to abrasion and do not promptly pull apart longitudinally upon releasing the outside resistance on the gear, in which case the release spring 60, 61 acts and the shoulders 64 of the wedgeblocks engaging the inner edges of the couplingr bars 66' will cause the friction plates to be moved outwardly with the followers bythe aid of the releasing spring. Y The action of this buffer mechanism is substantially the same when a pulling force is applied to the draft gear and then let go. In such a case the front buffer head, wedge block, wedge plates, friction plates and coupling bars remain relatively at rest while the corresponding rear members move forwardly, andupon cessation of the load the gear again relaxes into its normal condition as previously described with reference to a pushing load.

This shock *absorbing mechanism is very compact in construction and forms a complete unit by itself which can be entirely assembled inthe factory ready to be installed on a car without the necessity of shipping any loose or Separate partwith'the same or requiring 'the addition of any further parts for completin the same at the place where the same is to installed, as is the case with shock absorbers for'this purpose now on the market.

g 'Inorder to thus permit of shipping the apparatus assembled the several parts are held -in their proper relative position bypassing a tie bolt or ro'd .70. through openings'v .71, 2,

'formed centrally Yinpthe bu er heads andwe' blocksandengaging the head and nut 7 3 o this tiel'bolt with theoutersides of the dotted lines in Fig. 4.

The work or load in. this friction draft ear lis absorbed over a very large surface w ich rmits of employing a comparativel buffer' heads, sucha tie rod being shown by uaring pressure to obtain thede'sire frictional resistance between the plates without undue abrasion,l or wear and thus-ensuring ing uniform smooth operation inasmuch asno' longer life for the apparatus as well. as secur- Owing -to the employmentof a single spring system both forreleasin the gear as well as obtaining the .desired iction between the friction plates, the structure is greatly sim- :Moreover the spring-capacity is uti-V lized either when cushioning against buiiing or' pulling load as well as whenl releasing the gear after" the load is removed. Furthermore,

the several parts .of this'apparatus areselfaligning inasmuch ,as the same are guided upon each other` during the operation of the, parts of; r accom- '.ment between said wedge plates'and bloc -same an'd`do-nohdepend upon a-ny thefear which receives the same o plishing this purpose.

I claim as my invention:

- 1. A shock' absorbercomprisingtwosets of intercalated friction plates, two longitudinally movable followers which are arranged, re-

spectively, at the outer ends of the two sets of friction platesandeach of said followers adapted to effect the first part ofits inward movement while the respective set of frictiony plates is at'rest and toengage the outer ends of thesameand move therewith after the initialpart-'ofthe inward movement of the respectiire-` follower,l wedging means which operate to" press. the1 several 'friction plates together transversely and which are moved. inwardly and'caused to exert pressure by engagement' therewith of the' respective followers.y during the first part of the inward movement of said followers and to relieve said pressure durinfgthe outward movement of said wedgin means and the outward movement of sai followers, transversepressure 'resisting means supporting said friction ,plates and `wedging means relatively to one another and each of the sets of plates being spaced apart from the corresponding follower in the released condition ofthe absorber and spring means to hold the wedging means ,Y in engagement withthe plates and to release the mechanism after compression.

` 2. A shock absorber comprising a plurality of sets of -friction plates which are slidable lengthwise relatively to each other, the plates iof one set alternatin with those of the other,

-a plurality of simi ar buffer members one movable lengthwise relatively to the other and each en'gagin againstone end of one" set of plates and a o supporting said sets of.

iplates on one longitudinal side thereof, `wedgingmeans operating from the opposite longitudinal sides of said sets of plates for pressing the same together in a direction at right angles tothe longitudinal sliding movement of said plates, and means for retracting said lfriction plates when released from the effects of said wedging means comprising a releasing bar adapted to operate upon the wedging means during the opening' action of the absorber.

3. A shock absorber comprising a plurality` 'of-sets v'of friction plates which are slidable lengthwise relatively to each other and the plates of one set alternating with'another, a plurality of buiing members each engagin the outer endsof the'l plates of one set an also supporting-said plates on one longitudinal side thereof,- a plurality of wedge plates each engaging the vopposite longitudinal side of said-plates, a' plurality of longitudinally movable wedgev blocks each havin vretractedupon relaxing the wedg'ing engage;-

4. A shock absorber comprisinga plurality s lidingilengthwise lrelatively'to one another, aplurality of bufer members each supportwedging engagement with one of said weV geplates, spring means for releasing the wedge action of said wedge plates andblocks, and means y,forca'using said sets offriction plates to` be '11s l. of 4sets of co-operatigfriction plates which V" v alternate with each other and are capable vof sides andalso adapted toengage the outer,

ends'of thesame, a plurality of wedge plates 'each engaging with the-'opposite longitudinal 'side of one of said friction plates, a plurality of longitudinally-movable wedge blocks each having wedging enga ement `with one of said ing said plates on one of their longitudinal 1.20

(soy

6 'LT-rame ing said sets of friction plates to be retracted lengthwise with said blocks.

5. A shock absorber comprising a pluralityl of sets of co-operating friction plates which alternate with each other and are capable of sliding lengthwise relatively to one another, a plurality of buffer members each sup orting said plates on one of their longitusinal sides and also adapted to engage theouter ends of the same, a plurality of wedge plates each engaging with the opposite longitudinal side of said friction plates, a ,plurality of longitudinally movable wedge blocks each y having wedging engagement with one of said wedge plates, spring means for' moving said blocks in the direction for retracting the same from said Wedge plates, and means for causing said sets of friction plates to be retracted lengthwise with said wedge plates.

6. A vshock absorber comprising a plurality' of sets of co-operating friction plates which alternate with each other andare capable of.

sliding lngthwise relatively to one another, a plurali y of buffer members supporting said plates on one of their longitudinal'sides and also adapted to engage the outer ends of the same,.`a plurality of wedge plates each engaging with the opposite longitudinal side of said friction plates, a plurality of longitudinally movable wedgel blocks each having wedging engagement with one of said wedge plates, spring means'for moving said blocks in the direction for retracting the same from said wedge plates, and means for causing said sets of friction plates to be retracted lengthwise with said wed e blocks and wedge plates,

and a main spring operating on said wedge plates, and means for causing said friction plates t0 be retracted by the pressure of said springs. l

8. A shock absorber comprising a plurality of sets of friction plates which alternate with each other and are slidable lengthwiserela-v tively to one another, two longitudinally movable buffer members each adapted to engage the outer end of one of said sets of friction plates and one of the longitudinal sides of said plates,wedge plates engaging thel opposite longitudinal side of said plates at the ends thereof, wedge blocks ea'ch of which engages with one of said buffer members and also has a wedging engagement with an adjacent wedge plate anda spring resistance which forces the wedge means into engagement and returns themvagain to normal reg lease position.

9. A shock absorber comprising a plurality of sets of friction plates which alternate with each other and are slidable lengthwise relatively to one another, two longitudinallyI movable buffer members each adapted to engage the outer end of one of said sets of fric- 'tion plates and one of the longitudinal sides of said plates, wedge plates engaging the opposite longitudinal side of said plates at the ends'thereof,lwedge blocks each of which e11- gages .with one of said buffer members and also has a wedging engagement with an adjacent Wedge plate, and a main spring interposed between said wedge plates.

10. A shock' absorber comprising a plurality of sets of frictioniplates which alternate with each other and are slidable lengthwise relatively to one another, two longitudinally movable buifermember's eachv adapted to engage the outer end of one of said sets of friction plates and one of thelongitudinal sides of said plates, wedge plates engaging the opposite longitudinal side of said plates at the ends thereof, wedge blocks each of which-engages with one of said buffer mem= bers and also has a wedging engagement with an adjacent wedge plate, a releasing spring interposed between' said wedge blocks and a spring resistance which forces the wedge means into engagement and returns them again to normal release position.

ll. A shock absorber comprising two pairs of"sets of friction plates, the two pairs being` arranged lengthwise side by side and separated by an intervening space and the plates of one lset alternating and slidable longitudinally in engagement with the platesof the companion set, buffer members adapted to engage with the opposite outer ends of the several sets of friction plates and alsosupportingthe same on their outer longitudinal sides against transverse movement, means arranged in the space between said pairs of platesand buffer members and operating to produce outward transversey pressure against the inner longitudinal side of said friction plates, and means for relaxing the transverse pressure on said friction plates comprising a releasing bar adapted' to engage with said outward pressure means during the opening action of said absorber.

12. A shock absorber comprising two pairs of sets of friction plates, the two pairs being arranged lengthwise side by side and separated by an intervening space and the plates of one set alternating and slidable longitudinally in engagement with the plates of the companion set, buer members adapted to engage with theopposite outer ends of the several sets of friction plates and alsosupi porting the same on. their outer longitudinal 30 tween said wedge blocks, bridge plates each extending across the space between two wedge y with one of said bu er members and also having wedging engagement with the wedge plates at the corresponding ends of the friction plates, a releasing spring interposed bev tween said wedge blocks, and a maln spring interposed between the wedge platels'at one end of the friction latesand the vwedge plates 4at the opposite en of said friction plates.

.13. A shock absorber comprising two pairs of sets of friction plates, the two pairs being arranged.v lengthwise side by side and sepl arated by an intervening space and the lates.

of one set alternating and slidable longitudinally in engagementwi-th the plates of the companion fset, buffer members adapted to engage with the opposite "outer ends of the several sets of friction plates and also supporting the same on their outer longitudinal sides against transverse` movement, wedge plates engaging the inner longitudinal sides ofsaid friction plates adjacent to opposite ends thereof, wedge blocks each engaging with one of said buffer members and also havshoulders, buffer members engaging the outer:

ing wedging engagement with the wedge` plates at thel corresponding ends of the friction plates, a releasing spring interposed beplates at corresponding outer ends of the friction-plates and bearing .against these wedge plates, anda main springbearing at its opposite ends lagainst said bridge plates.

14. A shock absorbercomprising a pluralit of sets of co-operating friction plates w ich are slidable longitudinally and alternate with each other andthe plates of each set being provided with inwardly facing ends and one longitudinal side of said friction plates, wedge'plates engaging the opposite lon itudinal sides of said .friction plates, wedge locks having wedging engagement \with said wedge platesand provided with outwardly facing shoulders, coupling bars arranged between said shoulders on the wedge block andr theshoulders on'the adjacentsets of fricion platesand spring'l'means to hold the wedge plates in engagementwit-h the friction plates and to release the mechanism after compression. I

15.A shock absorber comprising a plurality of sets of coeoperatingv frictiony plates whicha're slidableV longitudinallyand alternate with each other and the platesf'ofeach set being provided with inwardlyffacing shoulders, buffer members engaging the outer ends and 'one longitudinal side` of said friction plates wedge plates engaging the opposite i longitudinalsides of said friction plates, and having outwardly facing shoulders, wedge blocks having wedging engagement with said y ranged Ilengthwise side byside, the plates of .one set of each pair alternating with the plates of the companion set and slidablc lengthwise relativelyto eachother, hollow 'buiiing members each having an outer end wall adapted to engage with the outer end of one set'of friction plates and side walls engaging the outer longitudinal sides of said friction plates, and, means interposed between the inner sides of saidbuifer members and friction plates for producing an outward pressure upon moving said buing members relatively-toward each other and to release-said pressure upon moving said buiiing members relatively away from each other.

` 17. In a friction shock absorber, the combination of a` plurality of-'sets of friction plates, the plates of each set being interca- -`lated with the plates of the other set and each set being movable lengthwise relatively to the other set, two followers, each of y which is associated with one set of friction plates and which is adapted to effect the initial part of its inward movement while Athe respective setof plates is at rest and to nieve inwardly with the respective set of the yadjacent follower and`having wedging A engagement with the Ashoes at the respective end of said plates, and a Vspring resistance interposed between4 the shoes at one end of the plates and theshoes at theopposite end of .the same.

18. In a friction shock absorber, the com bination of a plurality of sets of friction plates,`the 'plates of each set bein inter-- each set beingmovable'lengthwise relatively yto the other set, two followers, each of which is associated with one set o f friction plates and which is adapted to effect the initial part of its inward movement while Athe respective set of plates is at, restl and to moveinwardly with the respective set of plates after .the initial'part of the inward Amove*- ment of said followerhas been effected, shoes 1,20. calated with the plates of the other set and plates at opposite ends thereof and the shoes at each' end of the plates ai'lapted to moveV engagingltheisides of said sets of friction I posite end of the plates.

19. A'shock absorber comprisingtwo sets of intercalated friction membersytwo follower means' movable lengthwiseinwardly and outwardly. relative to .one another and each spaced from said sets of friction mem- A bersin the released' condition of the absorber and to effect the initial partof its Vinward stroke while the corresponding'setof friction members is at rest and each follower means being adaptedto engage the lrespective set of lfriction members and move with the same. longitudinally during tlie' re-V mainderof fsaid inward stroke', transverse Wedge pressure creatingmeans interposed between each'ffollower means and rsaid frictionmembers and haring co-operating wedge surfaces for causing the friction members to be ressed'transversely together with Aincrease y pressure upon moving one of said follower means longitudinally. inward relative r to the yother follower means, transverse ressure resisting means for supporting said riction members and'said transverse pressure creating means relatively to one` an.

other, anda vspringeresistan'ce'means which is increasingly stressed during compression of the mechanism; and means which carry the reaction of said spring resistance means past the co-operating wedge surfaces'of said transverse wedge ressure creating means to said'frictionmem ers for returning the latter tonormal position.

20. A`shock absorber comprising two sets.

of intercalatedl-friction members, two Afollower means `movable' lengthwise inwardly and outwardly and each spaced from one of said setsfof friction members inthe released condition ofjthe absorber and toI effect;the initial part of itsJ inward stroke while the corresponding; set of, frictio-membersis at rest' and each follower means adapted to end 'age the respective set of friction members uring the remainder of :saidinward`- stroke for causing the respective follower means and friction members toimove inwardly toether transverse -wed e ressure Creatin g a v .means interposed betweeneach follower 4means and the corresponding end of' said sets of friction members and having co-operating wedge surfaces for causing the friction members to be pressed transversely together with increased pressure upon moving one of said follower means longitudinally inward relativeto the other, transverse pressure resisting Lmeans at opposite endsof said sets of friction members for 'supporting'A said friction members and said transverse wedge pressure creating means relatively to one another, a spring resistance means; and means for causing said spring resistance means to move said sets of friction members longitudinally outward relative to oney another upon relaxing theiabsorber and operating on said friction members by carrying the pressure of said spring resistance means past the (io-operating -wedge surfaces of said transverse wedge pressure creating means.

21.l A shock absorber comprising two sets of friction members having their opposing v`inner ends intercalated, two follower means movable lengthwise inwardly and outwardly toward and from one another and each spaced apart from the outer end ofv one of said sets of friction members in thereleased condition y of the absorber andl to effect the initial part' of'its inward stroke while the corresponding set of friction members is at rest and each follower meansadapted to engage tlie'outer end of the respective set of friction members g5 and cause the respective moving follower means and corresponding set of friction mem bers to move lengthwise together during the remainder of saidinward stroke, transverse wedge pressure creating means interposed between each follower means and the corresponding ends of said sets of friction members and having. co-operating wedge surfaces or'causing the friction members to be pressed transversely together with increased pressure upon moving one ofA said follower means longitudinally inward relative to the other, transverse pressure resisting means at opposite ends of said sets of friction members -for supporting said friction members and said transverse wedge pressure creating means relatively to one another, a main spring resistance means; means for moving said sets of friction members longitudinally outward relative to one another upon relaxing the absorber and operating on said friction members by ca rying the pressure of said main spring re- -sist nee means past the co-operating wedge surfaces of said transverse wedge pressure creating means, and a releasing spring means interposed between said follower means for moving tlie same longitudinally outward.

- 22. A shock absorber comprising two sets of intercalated friction members,- two follower means movable lengthwise inwardly and outwardly and each spaced from one of said sets of friction members in the released condition of the absorber and to effect the initial part of its inward stroke while the corresponding set of friction members is at rest and each followermeans adaptedto engage thel respective set of friction members during the remainder of said inward stroke, and cause the respective follower means and friction members to move together, transverse wedge' pressure creating means interposed between each follower, means and the corresponding ends of said sets of friction members and having co-operating wedge'surfaces 4fory causing the friction members to be pressed transversely together upon moving one of said follower4 means longitudinally inward relative to theother, transverse pressure resisting means at opposite ends of said sets of friction members for supporting the latter and said transverse wedge pressure creating means relatively to one another, a main spring resistance means V lmitns for moving said sets of friction membersiongitudinallyoutward relative to one another upon removal of the loadand operatingontherespective friction members by carrying the reaction of saidmain spring resistance means past the co-operating wedgesuri faces of said transverse wedge pressurecreat-v ing means to the friction members, a releasing spring means interposed between said follower means for moving the latter longitudinally coupled with said frictionmembers for causing the latter to moveoutwardly with the foloutward and producing a clearance between said follower means and the outer ends of said friction members in the released condition of the mechanism, and supplemental restoring means Wher'ebythe releasing spring means is lower means.

23. A friction draft ear comprising op-` posed sets of intercalate friction plates slidable lengthwise relatively to each other, opposed follower means separated respectively from said sets of friction plates during normal condition of the gear and effecting an initial inward movement while the friction" plates are at rest and completing their inward movement with said friction plates, opposing wedging devices engaging said friction plates at opposite ends thereof and actuated bysaid follower means for creating transverse pressure on said friction plates, pressure resisting devices'supporting said friction plates and said wedging devices relatively to one another, spring resistance means lopposing inward movement of said wedging devices, and means for transferringexpanding pressure from said spring resistance means to said friction plates andpassing bythe co-operating angles ofsaid wedging devices for effecting i longitudinal return movement of the friction plates to their normal position.

` 524.V 'A shock .absorber comprisingtwo sets of intercalated friction plates, two-longitu- `dinall Vmovable followers which are arrange respectively, at the'outer ends of the two sets of friction plates andeach of said followers adapted toefect the first part of inward movement while 'the respective set of friction plates is at rest and to engage the outer ends 'of the same and-move therewith after the initial partjof the inward movement of the respective follower, wedging means which operateto press the several fricti'on plates together transversely and which are moved inwardly and caused to exert pressure by engagement therewith of i the respective followers during the first part of the inward movement of said followers and to relieve said pressure during the outward movement of said wedging means and :the outward movement of said followers,

transverse pressure resisting means supporting said friction plates against said wedgin means, land each of the sets of plates being spaced apart from the corresponding follower in the released condition ofthe absorber, and spring means -to hold the wedging means Vin engagement with the plates and to-release .the mechanism after compression, said spring means effecting the initial part of its expansion while the respective sets of friction plates are at rest and said spring means operating on said frictionA plates after said initial part of'its expansion and moving bo'thof said' sets of plates outwardly into their normal position.

525.y A shock absorber comprising two sets of intercalated friction members, two follower means movable lengthwise inwardly and outwardly. relatively to one another and veach spaced from one of said sets of friction members in the released conditionof the absorber and to effect the initial part of its inwardlstroke while the corresponding set of friction members is at'rest and each follower means adapted to engage the respective set of frictionmembers and compel the respective follower means and friction membersv to move longitudinally inward togetherl l during the remainder ofsaid `inward stroke,

transverse wedge pressure creating means interposed between each of said follower means-and the adjacent ends of said fricti'on members and having co-operating wedge `surfaces for causing the friction members of the respective sets to be pressed transversely l together with increased pressure' upon moving one of said follower means longitudi' nally inward relative to the other follower means, transverse pressure -resisting means for-supporting said friction-members of the respective sets in opposition to said transverse pressure creating means, arestoring spring resistance means which is increasloaded-vduring' compression of the' y said follower means.

l sets to be pressed transversely'together with leasing spring resistance interposed between 26. A shock absorber comprising two sets of intercalated friction members, two follower means movable lengthwise inwardly and outwardly relatively to one another and each follower means spaced from one of said setsoffriction members in the released condition of the absorber and to effect the .initial part of its inward stroke while the corresponding set ofl friction members is at rest and each follower means being adaptedv to engage the respective set of friction' members and move with the same longitudinally during the remainder of said inward stroke, transverse wedge pressure creating means inteqfiosed between each follower means and riction members and cooperating with said opposite ends of said friction members and having cooperating wedge surfaces for causing the friction members of the respective increased pressure upon moving one of said follower means Ilongitudinally inward relative to the other follower means, transverse pressure resisting means for supporting saidl sets of friction members and said transverse pressure creating means relatively to one an-v other, a spring resistance means increaslnly stressed during compression of the mec nism, and return means which carry the reaction of said spring resistance means to said friction members for returning the latter to normal position and which include. spring seats each interposedbetween said spring resistance and one of saidtrasverse wedge pressure creating means.'

JOSEPH M. HALL. 

